1. Field of the Invention
This invention generally relates to contact lens insertion and extraction devices and, more particularly, relates to contact lens insertion and extraction devices especially useful for soft contact lenses.
2. Description of the Prior Art
In the past, several prior art devices have been disclosed for the purpose of inserting and/or removing a contact lens. For example, U.S. Pat. No. 2,919,696 discloses a ram type device which is spring loaded and is used to insert a contact lens on an eye. One embodiment of this patent shown a bulb member which is used to apply a suction on the connecting tube for the purpose of removing a contact lens. This prior art device does not permit good visual indication of the contact lens during insertion or extraction operations with a mirror, does not have a means of preventing a soft contact lens from being sucked down the connecting tube during the extraction operation using the bulb, and cannot have the contact lens holder portion easily asepticized which is very important for soft contact lens use.
U.S. Pat. Nos. 3,177,874 and 3,091,328 disclose a contact lens applicator device and a contact lens inserter and remover device, respectively. The applicator device of U.S. Pat. No. 3,177,874 is not designed for removing a contact lens, does not have any means of preventing a soft contact lens from being sucked down the connecting tube, and cannot have the contact lens holder portion easily asepticized. The contact lens inserter and remover device of U.S. Pat. No. 3,091,328 is a fairly complex structure which uses both springs and a suction type bulb, does not permit good visual observation of the insertion and extraction operations, does not permit easy asepticizing of the contact lens holder, and does not provide a good gripping action on the back portion of the contact lens.
U.S. Pat. No. 3,424,486 discloses another contact lens handling device which uses a suction cup and a bulb type member for applying suction pressure to the suction cup. This device has a ninety degree bend to permit better visual observation of the contact lens handling operation with a mirror. The contact lens holder portion can be removed from the rest of the device, but the contact lens holder portion could not be used for a soft contact lens as there are no means for preventing a soft contact lens from being sucked down the connecting tube during the process of applying suction into the back of the soft contact lens.
U.S. Pat. Nos. 2,384,334 and 3,583,010 disclose various devices using pneumatic pick up features as described above or suction type cups, but these references are not believed to be as pertinent to the art of handling contact lenses as the other references cited in this specification.
U.S. Pat. No. 3,647,380 discloses a contact lens holder which has a contact lens holder that can be reversed to either provide a concave or convex surface for handling a contact lens regardless if it is up or down. This device has the disadvantage of not being very good for use with a soft contact lens because it cannot adequately grip the back surface portion of the soft contact lens. Furthermore, the device cannot be used well with a mirror.
U.S. Pat. No. 3,934,914 discloses a fairly complex device for inserting and removing a contact lens which includes a light transmitting member and shaft as an aid in sighting through the device during operation. This device is expensive and the rather large diameter walls thereof do not permit a good visual observation of the inserting and removing operations except possibly through the relatively narrow light transmitting shaft in the center of the device.
U.S. Pat. No. 3,879,076 is a fairly complex apparatus for applying and removing a soft contact lens which utilizes a removable contact lens holder portion that contains a number of ducts to permit suction to be applied through the ducts during the applying and removing operations. This apparatus recognized that there was a major problem in handling a soft contact lens with a pneumatic type device and utilizes a very expensive type of solution, namely, a contact lens holder with longitudinal-shaped ducts to provide a gripping action on the back surface portion of the lens without having the soft contact lens be sucked down the pneumatic tube. This apparatus is not only relatively expensive and complex, but does not permit good visual view of the soft contact lens applying and removing operations. Furthermore, it is not known whether the disclosed longitudinal ducts can provide a good gripping action by the plurality of relatively point type suction contacts and whether, in use, blockage of these small diameter ducts will be a problem.
Accordingly, a need existed to provide a relatively simple, low cost contact lens handling device which would be especially useful for handling a soft contact lens and overcome the disadvantages of the above cited prior art devices.